Judith, I wondered if this was worth putting up as a post on Arctic Sea Ice.
Might need some editing. Perhaps others here could take it and redraft it into something respectable without my bias. Sincerely angech
Yo yo ice, probability and natural variation..
While everyone has been focusing on CO2 and MGST a funny thing has been happening [at the forum] with the sea ice extents this last 8 months. Which should cause some scratching of heads and readjustments in the range we currently give to natural variability, in our assessment of the causes of sea ice growth and the reliability of Arctic and Antarctic temperature recording.
2018 had the lowest winter maximum extent of the last 40 years of the satellite record despite a promising early regrowth. As such it was expected that it could set a new low record for the minimum summer extent comparable to that of 2016. Arctic temperatures fluctuated much higher than average though possibly on a par with the last 4 years during the melting season. Robust claims were made but the ice stubbornly refused to play along. Arctic hurricanes and large sea swells were predicted to break it up very quickly but the ice stubbornly sat there melting very slowly on top of an even more unexpected slow volume loss.
Consequently when the minimum arrived despite the heroic high temperatures it had gone from the lowest maximum extent to the 8th lowest minimum in September. Skeptics were crowing and then it refused to refreeze dropping rapidly to the second lowest recovering extent in October.
Then weirdness set in with pockets of quick refreeze in November in areas, Barents and Chukchi, which were sadly lacking the previous year. The East Siberian Sea, stalwart in not melting early but a long slow late melt refroze overnight [well not quite but rapidly]. The Hudson Bay started to freeze and November offered up an impossible freezing sequence of 16 days of way well above average freezing rates despite the high temperatures. From 2nd lowest to 13th or 14th lowest in that time. Unprecedented, alarming freezing. The trend went from below 2010 to equal to the 2010 average and then, almost, to the 2000 average in that 16 days. Why? Silence.
As suddenly as it did the freeze it stopped. 2 weeks of below par freezing brought it back to the 2nd lowest. Then two human comedies. NASA mucked up with a graph on incomplete data that showed an impossible regrowth day that took 3 days to correct. Finally the last week into December. Ice growth recouped again helped by a shuffle at the end of December where growth rates are reset by the algorithms they use which give a jump to reflect an offset that develops each month [Masking].
Currently we sit in 8th place with a steep rise occurring and looking likely to continue.
What is to like? A recovery of sorts from the warm weather and currents stimulated by the 2016 El Nino and the 2017 rewarmth has occurred as expected due to the warming lag in these events finally wearing off. Further melting rate increase might occur in 4 months when the 2018 baby El Nino currents again reach the Arctic. This recovery might be big enough to give all concerned pause for thought as to how we should be assessing Arctic variability.
What is not to like? When 16 days can give a fluctuation that should normally take 10 or more years to develop without due cause [unpredicted, unprecedented] The problem is not with the fluctuations but the concept of how much natural variation is actually capable of occurring. These results strongly suggest that variability in the Arctic is much greater than the trends of the last 40 years predict.
The take home message is good for both sides. The last 10 years of data show a slowdown or pause in melting which might be the bottom of a cycle that is going to turn upwards if we choose to believe in 60 yar cycles. For warmists the fact that such large fluctuations can exist [independent of CO2 and surface temperatures] means there is also an outside chance of further large downward fluctuations.
JAXA ARCTIC EXTENT 6,731,603 km2?October 24, 2018?- Extent is lowest in the satellite record- Extent increase at 156 k is about 55 k ABOVE the average (2008-2017) on this day,
JAXA ARCTIC EXTENT 6,933,069 km2? October 25, 2018?- Extent is 2nd lowest in the satellite record,
– Extent increase at 201 k is about 110 k ABOVE the average (2008-2017) on this
JAXA ARCTIC EXTENT 7,182,053 km2? October 26, 2018?- Extent is 3rd lowest in the satellite record,
– Extent increase at 249 k is nearly 160 k ABOVE the average (2008-2017) on this day,
JAXA ARCTIC EXTENT 8,624,638 km2?November 5, 2018?- Extent is 4th lowest in the satellite record,
JAXA ARCTIC EXTENT 9,278,237 km2?November 14, 2018?- Extent is 6th lowest in the satellite record,
JAXA ARCTIC EXTENT 10,272,807 km2?November 22, 2018?– Extent is 13th lowest in the satellite record.
JAXA ARCTIC EXTENT 11,197,247 km2?December 11, 2018?- Extent is 2nd lowest
(JAXA)] ASI Extent. December 16th, 2018: [The error]
11,752,725 km2, an increase of 263,728 km2. 2018 is now the 9th lowest on record.
JAXA ARCTIC EXTENT 11,752,393 km2? December 22, 2018? – Extent is 4th lowest
JAXA ARCTIC EXTENT 11,871,945 km2? December 28, 2018? – Extent is 2nd lowest JAXA ARCTIC EXTENT 12,590,152 km2 ?January 4, 2019 – Extent is 8th lowest
[figures from others posting at Arctic Sea Ice Forum] * not a member